Device for limiting bending in a flexible means and key housing comprising same

ABSTRACT

A device adapted to limit the bending of a flexible tongue ( 15 ) in a bending direction includes an abutment ( 18 ) disposed in this direction at a distance ( 19 ) from the deformable end of the tongue ( 15 ). As a confinement device for a substantially flat object ( 7 ), includes a lower portion ( 1 ) supporting at least one locking element ( 15 ) flexible in a bending direction, and a member ( 18 ) for limiting bending of the locking element ( 15 ) in this direction. Application particularly to an electromagnetic automotive key housing with a removable button battery ( 7 ).

BACKGROUND OF THE INVENTION

The present invention is in the field of battery operated devices, inwhich confinement abutments are necessary. It relates in particular toblocking in position a button battery in a telecontrol housing (alsocalled a coded key), for opening/closing the doors of a vehicle.

DESCRIPTION OF THE RELATED ART

There are conventionally known automobile keys using an electronic codetransmitted to the vehicle when the user pushes on a button located onthe key. These keys generally require an internal source of electricalenergy, which usually takes the form of a button battery, which is athin disc, for example 16 mm in diameter and 2 mm thick.

Such batteries must be able to be installed when the key is first used,and then eventually be replaced when they become discharged afterseveral years. Thus, the housing of the key is conventionally made oftwo nesting parts, and the device for blocking the battery in positioncomprises one or several fixed abutments, of rigid plastic material, anda thin locking finger, whose flexibility permits, by resilientdeformation, introducing the battery in place, and which then returns toa position preventing movement of the battery from its recess.

It will be understood that such devices have the drawback that thelocking finger is very fragile, and handling, both during the firstinstallation of the battery as well as during replacement of the latter,can lead to breakage of the locking finger. The battery is then nolonger suitably blocked in its recess.

EP 0 5080 886 describes a confinement device for a flat battery of thebutton type by means of lugs and/or bearings associated with leafsprings adapted to effect electrical contacts. The problem this documentseeks to solve consists in avoiding leaving access to the electroniccomponents during changing the battery. The problem of wear and ofrupture of the lugs is not addressed.

DE4226578 describes an automotive remote control housing integrating adevice for confining flat batteries, of the button type, in which thebatteries are held in place by the cover and because of this fall uponopening the housing. There are no lugs or retaining means for thebattery in the lower part of the housing and the problem of wear and ofbreakage of these elements is not addressed.

SUMMARY OF THE INVENTION

The present invention solves the preceding problem and provides for thispurpose a device that is simple to make and inexpensive.

According to the invention, the device adapted to limit the bending of aflexible means in one bending direction, comprises an abutment disposedin this direction at a distance from the deformable end of the flexiblemeans.

The invention provides a device for confining a flat battery of thebutton type for an automotive key housing, comprising a lower portionsupporting at least one locking finger flexible in one direction ofbending, characterized in that the lower portion comprises an abutmentlimiting the bending of the locking finger in this direction, saidabutment being spaced from the locking finger in the direction ofbending sufficiently to permit the emplacement of the battery to beconfined whilst preventing the locking finger from leaving its resilientbending range.

Preferably, the means for limiting bending is an abutment disposed at asmall distance from the locking finger, in the direction of bending, thespace between the locking finger and the abutment being sufficient topermit the emplacement of the object to be confined whilst preventingthe locking finger from leaving its resilient bending range.

According to a particular embodiment, corresponding in particular to theuse for an electronic key housing, the device also comprises an upperportion, nestable on the lower portion, this upper portion comprisingpreferably a corner adapted to be disposed, when the housing isassembled, between the locking finger and the abutment.

It will be understood that this finger is adapted to hold the lockingfinger in blocked position of the confined object, when the housing isclosed.

To limit the movement of the object confined in the case of breakage ofthe locking finger, the upper portion of the housing preferablycomprises a projection bearing on the object, when the upper portion isassembled on the lower portion.

BRIEF DESCRIPTION OF THE DRAWINGS

The description and drawings which follow permit better understanding ofthe objects and advantages of the invention. It is clear that thisdescription is given only by way of example, and is not limiting incharacter.

In the drawings:

FIG. 1 shows in a plan view a lower portion of an automobile key;

FIG. 2 shows a cross-sectional view of the key housing;

FIG. 3 shows schematically a side cross-sectional view of a modificationof the device according to the invention.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

An automobile code key conventionally comprises a housing in two parts:a lower portion 1 and an upper portion 2. These two parts 1, 2 fittogether by a releasable nesting device 3, conventional in nature andnot described here in detail.

The code key thus usually comprises in its upper portion 2 a controlbutton 4 whose pressure actuates an electronic circuit 5 adapted to sendan electromagnetic identification message to a distant vehicle.

In present devices, the key also comprises blade 6, adapted to start thevehicle.

So as to supply the electronic circuit 5, a battery 7, of the buttonbattery type, is disposed in the bottom of the lower part 1 of the keyhousing, forming a base.

The button battery 7 rests on a leaf spring 8, to facilitate its removaland to ensure electrical contact with one of the terminals of the buttonbattery 7. This leaf spring 8 is secured by being forcibly sunk on a pin9, and its second end 10 serves as a point of first supply contact withelectronic circuit 5.

A second spring ensures electrical contact with its first end 11 withthe other electrode of the button battery 7, and its second end 12serves as the second electrical supply contact for the electroniccircuit 5. It will be understood that these two springs thus permit thesupply of the electronic circuit 5 by the button battery 7, removablywhen the two portions of the housing are separated.

The button battery 7 is held in position in its recess, on the one handby two rigid abutments 13, 14, of substantially inverted “L” shape,comprising a lug extending slightly above the button battery 7, disposedfor example at about 90° from each other along the circumference of thebutton battery 7.

On the other hand, a flexible locking finger 15 is disposed on the lowerportion 1 of the housing so as to be located substantially along thecircumference of the button battery 7, in a position opposite the rigidabutments 13, 14.

There will be defined hereafter in the description, a bending directionof the locking finger 15 (which here is common to the direction definedby the locking finger 15 and the center of the button battery 7),corresponding to the plane II—II in FIG. 1, a transverse direction asbeing the direction perpendicular to the securement direction in theplane of the button battery 7, and a vertical direction as being thedirection perpendicular to the principal plane of the key (which is tosay perpendicular to the plane of FIG. 1).

This locking finger 15 comprises a thin blade 16 extending substantiallyalong the vertical direction, and being in a portion extending above therecess of the button battery 7. This thin blade 16 has its leastthickness in the bending direction, and because of this, it gives to thelocking finger 15 its flexibility in this direction. In the presentnon-limiting example, this thickness is of the order of 0.5 mm.

The upper portion 17 of the locking finger 15 is beveled such thatsimply bearing on a button battery 7 disposed above its recess givesrise to the elastic return by bending of the locking finger 15 in thebending direction, and permits the passage of the button battery 7toward its recess.

An abutment 18 for limiting the elastic return of the locking finger 15is disposed slightly behind the deformable end (upper) of the lockingfinger 15, in the bending direction of the locking finger 15.

The spacing 19 left between the locking finger 15 and the abutment 18for limiting elastic return, is sufficient to permit the emplacement ofthe button battery 7, whilst preventing the locking finger 15 fromleaving its resilient range of bending in the bending direction.

The abutment 18 is preferably made of “T” shape, as is seen in FIG. 1,with a flat portion 20 substantially parallel to the thin blade 16 ofthe locking finger 15, and a mechanical reinforcement 21 perpendicularto this flat portion 20, and for example of substantially triangularshape, as shown in FIG. 2.

The abutment 18 is preferably of a height suitable to bear against theelectronic circuit 5, when the key housing is closed, so as to ensurebetter mechanical holding of this latter.

The rigid abutments 13, 14, the locking finger 15 and the limitingabutment 18 are made in the conventional manner, and for exampledirectly during molding of the lower portion 1 of the housing.

In a modified embodiment, shown in FIG. 3, the upper portion 2 of thekey housing comprises a wedge 22 adapted to be disposed, when thehousing is assembled, between the locking finger 15 and the abutment 18.The upper portion 2 of the housing also comprises a projection 23 forbearing on the button battery 7, when the housing is closed. Thisprojection 23 is adapted to prevent the button battery from leaving itsrecess, if the locking finger 15 were to be broken and hence no longerhold the battery in place.

In another modification, a spring abutment 24 is disposed below thesecond end 10 of the leaf spring 8, so as also to limit the clearance ofthis end of the leaf spring, and hence to reduce the risk of permanentdeformation or breakage.

In still another modification (FIG. 3), the button battery 7 is disposedon a base formed in the lower portion 1. This base being disposedslightly above the foot of the locking finger 15, thereby defining acomplementary height 25, which increases the resilient flexibility ofthe thin blade 16.

In still another modification (not shown), the rigid abutments 13, 14are replaced with flexible locking fingers 15, these locking fingers 15comprising abutments 18 for limiting bending.

What is claimed is:
 1. Device for holding a flat battery (7) of thebutton type for an automotive key housing, comprising: a lower portion(1) supporting at least one locking finger (15) flexible in one bendingdirection, the lower portion (1) comprises an abutment (18) for limitingbending of the locking finger in the bending direction, said abutmentbeing spaced from the locking finger in the direction of bendingsufficiently to permit the emplacement of the battery (7) to be confinedwhilst preventing the locking finger (15) from exceeding a resilientbending range of the locking finger, the abutment (18) being of T shape,with a flat portion (20) perpendicular to the bending direction of thelocking finger (15), and a mechanical reinforcement (21) parallel to thebending direction of the locking finger.
 2. Device according to claim 1,further comprising an upper portion (2), receivable on the lower portion(1), this upper portion (2) comprising a wedge (22) adapted to bedisposed, when the housing is assembled, between the locking finger (15)and the abutment (18).
 3. Device according to claim 2, wherein the upperportion (2) of the housing also comprises a projection (23) bearing onthe battery (7), when the upper portion (2) is assembled on the lowerportion (1).